The invention relates to jaw crushers as used in mines or in aggregate producing industries as a primary crusher.
Prior art jaw crushers can be classified into three types, namely single toggle jaw crushers, double toggle jaw crushers, and dodge jaw crushers. Dodge type jaw crushers have very little usage and single toggle jaw crushers are simple in construction and light weight so they have advantages in portable crushing plants. Double toggle jaw crushers are rugged and heavy, so they are usually used in big stationary crushing plants.
Although single toggle jaw crushers are simple in construction and light weight, the eccentric shafts and bearings are located in the upper parts of the crushers and are used to directly apply the significant forces needed to crush heavy aggregate. Particularly with hard materials to be crushed bearings wear is substantial and bearing life is short and as the orbit of a movable jaw is not linear, that is the orbit of the upper part of movable jaw describes a circle and the lower part of a movable jaw describes an elliptical or upwardly slanting line, the wear rate of a jaw liner is high particularly as compared to that of a double toggle jaw crusher. A type of single toggle jaw crusher of the prior art is shown in
A double toggle jaw crusher has a movable jaw suspended by a large bushing and pin assembly with the movable jaw driven back and forth by a double toggle. The double toggle is connected to a pitman that is powered by an eccentric shaft. In a double toggle jaw crusher, the force required to crush aggregate like large stones is primarily exerted by the bushing pin assembly. As the double toggle acts as a force magnifying device, the force that is exerted on the bearings of the eccentric shaft is small compared to that of a single toggle jaw crusher, generally ⅕ or ⅙ of the force. As a result, the life of the bearings are much longer in a double toggle jaw crusher as compared to the prior art single toggle jaw crushers. In addition, the life of the jaw liners of a double toggle jaw crusher are much longer due to linear movement of the movable jaw.
However, a double toggle jaw crusher is much larger than a single toggle jaw crusher due to the long double toggle and the orientation of the size adjusting mechanism for adjusting the size of crushed stones exiting the crushing chamber. This requires the construction of larger and heavier double toggle jaw crushers which are more costly than a single toggle jaw crusher of equivalent capacity. As a consequence, there is a need for a jaw crusher that has the size, weight and simplicity of construction advantages of single toggle jaw crushers with the durability of a double toggle jaw crusher.
Referring initially to
Referring to
Two side plates 50 extend in parallel spaced alignment on both sides of crusher 10. Plates 50 are rigidly attached to stationary jaw assembly 20 at one side and to side plate connecting pipe 51 and reinforcing plate 53 to define the frame of crusher 10. As seen in
Movable jaw liner plate 32 is attached to inner face 34 of movable jaw assembly 24 by being wedged against angled flange 36 by means of wedge 38 and wedge bolt 40 attached to movable jaw assembly 24 by means of nut 42. Movable jaw liner plate 32 may be removed by removable nut 42 and bolt 40 thereby releasing wedge 38 for the removal and replacement of movable jaw liner plate 32 when movable jaw liner plate 32 becomes worn. Similarly, stationary jaw liner plate 22 may be removed and replaced when it becomes worn.
A pair of spaced opposed cheek plates 44 (
Lever 48 is rotatably connected to side plates 50 positioned adjacent each side of movable jaw assembly 24, as best seen in
Housing 56 further includes hydraulic jack access chamber formed at the rear end of housing 56 adjacent end wall 68. End wall 68 further includes opening 72 which permits a hydraulic jack to be inserted to apply pressure on adjusting block 60 through openings 74 in plate 66, as seen in
Lever 48 includes upper extension 76 extending upwardly from housing 56 and angled rearwardly, in a direction away from movable jaw assembly 24. Upper extension 76 forms a second extension extending from pivot axis 54 which is positioned with respect to housing 56 and adjusting block 60 to cause leveraged force to be applied to housing 56 and adjusting 60 on movement of upper extension 76 to cause lever 48 to move about pivot axis 54.
Eccentric shaft 78 is connected to side plates 50 for rotation about the longitudinal axis of shaft 78. Two types of eccentric shafts 78 are depicted in
Referring to
Pitman bearings 114 are positioned at both ends of eccentric part 104 of shaft 78. Eccentric part 104 contacts pitman bearings 114 which translate rotational movement of shaft 78 into reciprocating motion of roller body 21 which contacts upper extension 76 of lever 48 thereby imparting reciprocating motion on upper extension 76. A pulley and motor may be attached to an end of axial extension 106 to rotate shaft 78 about axis 112. Because applicant's invention employs lever 48 to drive toggle plate 62 eccentric part 104 may be manufactured to extend much further from axis 112 as compared to prior art eccentric shafts. For example, if lever 48 magnifies the force exerted by roller body 21 three times, eccentric part 104 can be dimensioned to permit movement of the eccentric part 104 against upper end 102 of extension 76 a distance which is three times greater than the distance moved by movable jaw assembly 24. Main bearing housing end cover 116 is used to cover one of the extensions 106 and prevent dust and dirt from entering the region around extension 106.
Because eccentric part 104 is relatively large it can be expensive and difficult to machine. As a consequence, I have developed a sectional shaft shown in
Note that bearings 108 and 114 are preferably rolling type bearings. However, the two pitman bearings 114 may be replaced with journal bearings in which case lubrication should be undertaken with an oil-based lubricant.
Lever 48 includes spring biasing system 84. Spring biasing system 84 includes inner tension rod 86 extending through hole 88 in upper extension 76. Inner end 90 of rod 86 is hook-shaped to engage latch 92 which is connected to movable jaw assembly 24. Outer end 94 of rod 86 is threaded and nut 96 may be positioned on outer end and tightened inwardly in the direction of movable jaw assembly 24. Spring 98 is interposed between nut 96 at its outer end and spring support 100 on extension 76 at the inner end of spring 98. Spring support 100 also has a hole. It can be appreciated that with nut 96 tightened downwardly to provide tension on spring 98 that spring 98 will bias or urge rod 86 outwardly which will cause movable jaw assembly 24 to likewise be urged outwardly so that movable jaw assembly 24 is positioned in its open position, that is in its position furthest away from stationary jaw assembly 20 with outlet 46 in its fully open position. The bias of spring 98 further causes movable jaw assembly 24 to push outwardly against toggle plate 62, adjusting block 60 and adjusting steel plate 66 against end wall 68. Further, the bias of spring 98 also causes lever 48 to pivot about pivot axis 54 so that upper end 102 of extension 76 contacts roller body 21. It should further be noted that when outlet 46 is in its fully open position, as depicted in
It can be readily appreciated that lever 48 acts as a force amplifying device in the same manner as a mechanical lever. Force applied on upper end 102 would be magnified and the resultant force on toggle plate 62 will be increased from the force applied at upper end 102.
Referring to
Movable jaw shaft 28 rolls down along the surface of right wall 127 during the discharge stroke, that is movement of movable jaw assembly 24 away from stationary jaw assembly 20. During discharge stroke movable jaw assembly 24 moves from closest position of
The movement of movable jaw shaft 28 within bearing 30 is only 2 or 3 millimeters even in large jaw crushers and the angle of rotation of movable jaw shaft 28 is less than one degree. This is a very difficult condition to solve in prior art bearings, namely pin and bushing assembly. In a pin and bushing assembly, a small angle of rotation and strong force make lubrication a very difficult task because in order to maintain a proper lubrication film under strong force between the surface of pin and bushing with some speed of rotation (for example 1 meter/sec) a continuous supply of lubricant is essential. In prior art crushing machines attempts to solve the problem of providing a continuous supply of lubricant were undertaken using a circulation pump. But this did not solve this problem at a low speed of rotation. If the speed of rotation of the shaft is low, lubrication film is destroyed and frictional wear between the pin and the bushing occurs. Lubricant supplying devices are also complicated and costly and cause many maintenance problems as well. Normal rolling bearings are expensive and quite big in size. Rolling bearings used in prior art single toggle jaw crushers as depicted in
The special rolling bearing of present invention reduces significantly maintenance cost and associated problems, particularly problems of lubricating movable parts in a dusty environment. This also reduces manufacturing cost. But it should be noted that although the use of the rolling bearing of the present invention is preferred, the jaw crusher of the present invention with the lever can adopt a pin and bushing assembly as well, if it is appropriate.
A second embodiment of the invention will now be discussed with reference to
A portable jaw crusher plant 149 is designed to travel on roads and its height is restricted by governmental laws and regulations. The highest part of a jaw crusher plant 149 is normally hopper 142. In order to lower the height of hopper 142 to ensure compliance with height regulations for road transportation, the height of feeder 140 which forms the bottom of hopper 142 must be lowered. Feeder 140 is located above and adjacent stationary jaw assembly 20, and stationary jaw assembly 20 may be slanted in order to lower its height to enable feeder 140 and hopper 142 to be lowered to reduce the overall height of plant 149.
In this embodiment of the invention, the structure of the lever assembly is different from that of
In the type A lever depicted in
In the type B lever depicted in
Lever shaft 200 which supports lever 150 is located below opening 160 rather than above opening 58 in the embodiment of
The upper end or second extension 252 of lever 150 is in contact with eccentric roller 210 which operates to impart reciprocating motion on second extension 252 in the same manner as previously described with respect to the first embodiment depicted in
The direction of the movement of the upper end 252 of lever 150 of
The other end of tension rod 218 is connected to movable jaw assembly 24 as in
So in this embodiment, one more tensioning means 232 is located on the upper part of the movable jaw assembly 24. Tensioning means 232 includes tensioning rod 234 connected to hook 236 attached to an upper rear portion of movable jaw assembly 24. Nut 238 compresses spring 239 which causes force to be applied on rod 234 to pull movable jaw assembly 24 in the direction of lever 150 forcing shaft 28 against a bearing side wall (not shown).
A nut hole and bolt combination 242 is positioned on the top 244 of opening 160 to prevent movement of adjusting block 170 when the adjusting block 170 and the toggle plate 172 are assembled.
In the second embodiment of
Roller seat 171 is fixed on an end of adjusting block 60 and roller seat 129 is fixed on head 132 of movable jaw force transfer plate 131. Foot 133 of movable jaw force transfer plate 131 is fixed to the back plate of the movable jaw assembly 24. Force transfer roller 141 is supported by flange 134 and is sandwiched between seats 171 and 129. When lever 48 pushes movable jaw assembly 24 toward stationary jaw assembly 20, force transfer roller 141 rolls upward along the face of the roller seat 129 and it rolls down along the face of the roller seat 171. This rolling motion is reversed when movable jaw assembly 24 moves away from stationary jaw assembly 20 when assembly 24 moves to its rest position as depicted in
Now referring
The principle and mechanism of supporting lever 48 and movable jaw assembly 24 is all the same. So in referring to
Lever support plate 180 has a head 181 and a body 182. The body 182 is rigidly attached to side plates 50 to receive the crushing force of rocks. The head 181 is narrower than the body 182 and it enters into lever 48 between the side plates 50 of lever 48. The head 181 has two cover plates 183 that are attached to the head 181 rigidly by embedded bolts 184.
The head 181 also has a heat treated roller seat 185 covering the vertical inner face of the head 181.
Base plate 186 of the head 181 is vertical to the roller seat 185 and it supports a portion of the weight of the lever 48 when the lever 48 is not in operation.
The head receives cylindrical lever roller 187 within the space made by the base plate 186 and two side cover plates 183 and the roller seat 185, and support the lever roller 187 securely.
The lever roller 187 is in contact with lever angle 188 which is fixed to the inner surface of back plate 47 of lever 48. The inner surface of the lever angle 188 fits well to the surface of the lever roller 187 and it has some grip on the lever roller 187. So there is no slip between the lever angle 188 and the lever roller 187 and it moves together when the lever 48 is in operation.
In the stroke in which lever 48 pushes the movable jaw assembly 24 towards the stationary jaw assembly 20, the lever roller 187 rolls up along the surface of the roller seat 185 just like the movement of the movable jaw shaft in
As explained above the same principle and mechanism are applied to the movable jaw support system. Movable jaw hanger 23 has a slanted vertical inner face 25 and ceiling flange 29 and a replaceable moveable jaw angle 27 is assembled to the inner surface of the moveable jaw hanger 23. Under the moveable jaw angle 27 is placed a long moveable jaw roller 19 and the moveable jaw roller 19 is supported by an angle shaped head 59 of movable jaw support plate 55. Moveable jaw support plate 55 is fixed rigidly to upper frame 26 to support the crushing force of rocks.
The head 59 of the moveable jaw support plate 55 has a slanted vertical and a slanted horizontal faces and they are covered by hard heat treated linings 591 and 592. The operation of this moveable jaw single roller bearing is same as that of lever single roller bearing.
One thing to be noted is that when the moveable jaw is not crushing rocks (for example when running empty or in the return stroke) there may be slip between the roller 19 and linings 591 and 592. In this case the load on the single roller bearing is only the weight of the moveable jaw 24 and the angle of rotation of the roller 19 is very small, the wear of the roller 19 and linings 591 and 592 is negligible.
In large jaw crushers, the weight of lever 48 reaches 10 tons and it is difficult to prevent the slip of lever roller 187 by the biasing force of spring 981 (
In
Hydraulic cylinder 401 includes a piston 404 positioned within cylinder 401 for reciprocal movement axially within cylinder 401. Outer surface 399 of the piston 404, includes a half sphere groove 398 and a first end 410 of piston rod 406 is fitted in groove 398. On the upper part of the lever 450 facing the hydraulic cylinder 401, are positioned holes corresponding to the number of hydraulic cylinders 401 employed. The piston rod seat 405 includes a half sphere groove and a fixed washer 409 to admit the second end 411 of the piston rod 406 in the same manner as piston 404. First end 410, and second end 411 of piston rod 406 are of spherical shape and include a threaded inner core hole 397. Ends 410 and 411 are attached to piston rod 406 by threads formed at the end of piston rod 406. The spherical ends 410 and 411 of the piston rod 406 are kept in position by a washers 408 and 409 respectively which are fixed by bolts 396 to piston 404 and piston rod seat 405. A hole 394 with thread is formed on the end cap 395 of hydraulic cylinder 401. Pipe 407 is threaded into hole 394 in end cap 395 of hydraulic cylinder 401, to admit hydraulic oil.
On the upper part of the lever 450 facing the hydraulic cylinder 401, are positioned holes corresponding to the number of hydraulic cylinders 401 employed. Each hole includes a fixed pipe 402 of similar diameter as that of hydraulic cylinder 401.
Hydraulic cylinder 401 is protected from dust by cone shaped rubber membranes 413. One end of the rubber membrane is connected to the rubber membrane flange 418 which is attached to flange 412 by bolt 403. The rubber membrane flange 418 includes a short tube 419 extending perpendicularly with grooves on its outside periphery.
Rubber membrane 413 is fixed on the tube 419 by compressing it with ring 420, which is forced over tube 419 and membrane 413 to retain membrane 413 between ring 420 and tube 419. The other end of rubber membrane 413 is fixed by sandwiching membrane 413 between ring 421 and grooves 392 which are formed on piston rod 406 near the spherical end 411. The rubber membrane 413 has a drain pipe 414 to let out small amounts of leaking hydraulic oil to an hydraulic oil tank (not shown). Stop 415 is made of rubber and restricts lever 450 when it moves toward the movable jaw assembly 24 to the certain limit and defines the starting point of the movement of the lever 450.
The interior of the hydraulic cylinder 401 is covered by a hard heat treated liner 417 inside of cylinder 401. Piston 404 includes piston rings 4041 which provide an effective seal of hydraulic oil with piston liner 417. The half sphere shape grooves on pistons are lubricated by leaking hydraulic oil and the grooves on the piston rod seats are lubricated by grease that is supplied through grease nipple 422.
Hydraulic pump 460 supplies a constant amount of high pressure hydraulic oil to cylinder 401. Timing valve 461 closes and opens periodically, for example 100 to 300 times per minute, to cycle between a position where hydraulic pressure is applied to cylinder 401 and a position where no hydraulic pressure is applied to cylinder 401.
Relief valve 462 opens when excessively high pressure develops in the high pressure line of the circuit. This situation occurs, for example, when unbreakable objects such as ironware products are in crushing chamber 18 of crusher 10.
When no hydraulic pressure is delivered to cylinders 401, timing valve 461 is in its open state. In that state lever 450 pushes on hydraulic cylinders 401 until lever 450 is in contact with the stop 415 by the force of springs 416 and by the force of springs of other biasing system (see
Hydraulic pump 460 supplies hydraulic oil to the circuit. When timing valve 461 is open, the hydraulic oil returns to the hydraulic oil tank 463, and there is no movement of the hydraulic cylinders 401. Hydraulic pump 460 is driven by an electric motor (not shown) or by an engine (not shown) and its operating speed is normally over 1500 rpm. Because the hydraulic pump operates at this high rate of speed it is advantageous to connect the shaft of the hydraulic pump to the shaft of the prime mover directly.
Because the crushing action of a jaw crusher 10 is intermittent, there is a need to store the energy of a power unit or prime mover during the non crushing cycle of the crusher 10 by mechanical means.
In this invention, a flywheel is mounted on the shaft of the prime mover. The rotational speed of a prime mover is several times higher for example 69 times than that of the eccentric shaft of a jaw crusher. So a smaller flywheel can store the same amount of kinetic energy as a big flywheel of a jaw crusher of the prior art. This helps reduce the weight and the cost of the jaw crushers 10 of the invention.
When the hydraulic pump 460 reaches its normal speed, the timing valve is set to open and close periodically by starting the driving motor of the timing valve. When the timing valve 461 is closed, the hydraulic oil enters the hydraulic cylinders 401 and the hydraulic cylinders push the lever 450 and the movable jaw assembly 24 crushes stones 12. When timing valve 461 opens the hydraulic oil from the hydraulic pump 460 together with oil from the hydraulic cylinders 401 which are forced to retract by spring 416 returns to the hydraulic oil tank 463 through timing valve 461. At the same time lever 450 moves toward hydraulic cylinders 401 until it is stopped by stop 415 on the square pipe 400. During this cycle, the accumulator 464 accepts some amount of hydraulic oil and releases it when the timing valve 461 is closed. This action of the accumulator 464 reduces the hydraulic hammering effective due to the relatively long return conduit to hydraulic oil tank 463.
When the timing valve 461 closes, the crushing action of the crusher 10 repeats. If uncrushable material such as the tooth of hydraulic backhoe enters into the crushing chamber the relief valve 462 opens thereby protecting the hydraulic circuit from excessively high pressure.
The body of the valve can be divided into high pressure part 466 and low pressure part 468. The low pressure part 468 includes a separable end cover 445 and a short pipe shaped guide 423. Flange 447 is positioned at the inside end of the guide 423 to prevent the poppet 438 from retreating beyond a predetermined position. A guide bushing 424 is fitted inside guide 423 and oil seal 425 is fitted at the outer end of guide 423. Shaft 426 of the poppet 438 is positioned in guide bushing 424 for slide-able reciprocating movement within guide bushing 424 between pre-determined limit defined by flange 447 at one end and poppet seat 440 at the other.
Shaft 426 has annular ledge 470 adjacent one end and spring washer 427 is located adjacent ledge 470.
Spring washer 427 is in contact with two springs, opening spring 428 and closing spring 429. Closing spring 429 is in contact with follower housing 430 at its other end. Follower housing 430 has a guide hole 431 and one end of shaft 426 fits within hole 431. Follower housing 430 is free to slide a short distance on shaft 426. At the end of shaft 426 there is a threaded part and a nut 432 is assembled on it to receive the force of springs 428 and 429. Guide 431 of follower housing 430 is lubricated by grease that is fed by grease nipple 422.
Follower housing 430 includes follower shaft 433 and follower 434. Follower 434 is assembled on follower shaft 433 using two rolling bearings 435. Follower 434 is driven by the cam 437 on shaft 436 of the prime mover 480 such as an electric motor or a hydraulic motor.
The body of valve 461 can be divided into two parts, high pressure part 466 and low pressure part 468 with poppet seat 440 dividing the two parts. When the poppet 438 closes the valve 461, poppet 438 receives a large force equal to the differences of the pressure between the high pressure part 466 and low pressure parts 468.
This large force is compensated by the balance piston 439, so that the opening and closing of hydraulic valve 461 is effected only by the force of springs 428 and 429 and the follower 434.
The closing spring 429 is stronger than the opening spring 428 and when the follower housing 430 pushes the poppet 438 to close the valve 461, only the opening spring 428 is compressed till the poppet 430 is in contact with the poppet seat 440. After the poppet 438 is in contact with the poppet seat 440, the closing spring 429 is compressed as well and the follower housing 430 moves against shaft 426. The distance of movement is adjusted to be small by the shape of cam 437.
The outer periphery of cam 437 is composed of two half circles of different radii which causes the poppet 438 to be in a completely closed or open state.
The valve opening cam 441 is positioned on the shaft of the prime mover to determine the position of the cam 437 and to open the timing valve 461 when the prime mover is stopped. Valve opening cam 441 has an eccentric extension which acts against the elastic force of plate spring 442 and together with follower 444 rotates shaft 436 of the prime mover to open hydraulic valve 461 when the prime mover stops driving the follower 434.
As it's shown in
Advance switch 510 is positioned to contact the lever cam 543 when the upper part of lever 450 touches stop 415.
Advance switch 510 is connected in parallel to switch terminal 520 of magnetic contactor 522 which drives the solenoid hydraulic valve 530 (
The retract switch 512 is always in a closed state in its rest position and the advance switch 510 is always in an open state when it is not actuated by lever cam 543, as depicted in
Referring to
If electric power is supplied to the control circuit depicted in
The driving motor (not shown) of the hydraulic pump 460 of
When solenoid hydraulic valve 530 is closed, the hydraulic oil supplied by the hydraulic pump to valve 530 goes to the hydraulic cylinders 401 forcing movable jaw assembly 24 toward stationary jaw assembly 20 to crush rocks 12. The upper part of lever 450 and lever cam 543 move in a direction opposite to the direction of movement of movable jaw assembly 24 and advance switch 510 is opened when cam 543 ceases to actuate switch 510 as cam 543 is moved to a position where it no longer contacts switch 510.
Because switch terminal 520 of magnetic contactor 522 is activated magnetic coil 514 is still supplied with electric current to keep the magnetic contactor 522 in its closed state. This state continues until lever cam 543 touches retracting switch 512 and opens switch 512.
When retract switch 512 is open, the supply of electric current to magnetic coil 514 is cut and magnetic contactor 522 is opened. When magnetic contactor 522 is open, solenoid hydraulic valve 530 is opened by the force of spring 428. Then movable jaw 24 retracts by the force of spring 428 until lever cam 543 contacts and activates the advance switch 510. When lever cam 543 activates advance switch 510 the cycle repeats and jaw crusher 10 crushes rocks 12.
The foregoing describes two types of hydraulic cylinders for driving movable jaw assembly 24, namely an open circuit type and a feedback circuit type. But it should be understood that there are many other variations of hydraulic circuits within the scope of the invention.
Number | Name | Date | Kind |
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4361289 | Georget et al. | Nov 1982 | A |
4659026 | Krause et al. | Apr 1987 | A |
4768723 | Fritz | Sep 1988 | A |
4899942 | Bohringer | Feb 1990 | A |
6619576 | Togashi et al. | Sep 2003 | B1 |
6644577 | Togashi et al. | Nov 2003 | B1 |
Number | Date | Country | |
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20040129814 A1 | Jul 2004 | US |